1. Field of the Invention
The present invention relates to a power conversion apparatus including a power module and a capacitor.
2. Description of Related Art
Electric vehicles and hybrid vehicles are provided with a power conversion apparatus which operates to convert DC power supplied from a battery to AC power for driving a motor mounted thereon. The power conversion is carried out by controlling switching on/off of switching elements of a power module included in the power conversion apparatus. Meanwhile, a surge voltage occurs in such a power conversion apparatus when the switching elements are turned on and off due to inductance arising from the wiring of its internal circuit. Accordingly, it is necessary to reduce such inductance.
Japanese Patent Application Laid-open No. 2010-35345 describes a power conversion apparatus devised to reduce such inductance. This power conversion apparatus has the structure in which a power module and a capacitor are connected to each other through a wiring board including a pair of conductor plates laminated on each other through an insulating sheet. The directions of currents flowing respectively through the conductor plates are opposite to each other. Accordingly, the inductance due to the conductor plates is small.
However, since the inductance due to a current path in the capacitor and a current path in the bus bar drawn from the electrodes of the capacitor cannot be reduced by such a structure, it is difficult to expect sufficient reduction of the surge voltage in the power conversion apparatus described in the above patent document.